This is something I've always wondered, is Star Trek communist? After all, they got no money of sorts, which screams communism to me. But they also promote human rights and diversity which anyone who's looked at any communist nation know they don't promote that kind of rights.

I don't think Star Trek is truly Communist. It may resemble a communist society, but it's really a society where noting is scarce anymore. As anyone can replicate what they need, there is no limitation of resources, which means there's no need for money, (in theory anyway). It may resemble communism, but it's really a system that's not possible today because of limited resources we have.

It's definately a commuinist society, but one portrayed as benign and benevolent on the surface but not always. the obvious show that comes to mind is TNG, where they did consider individual rights below the worth of the 'group'. There's even an episode where Picard is willing to allow an entire planet die in the name of political directives. We also see the Federation allow many of its own citizens to die for the 'greater good' several times.